[docker/cli] Deprecated project ScatterHQ/Flocker given as example in docs/extend/plugins_volume.md

### ROOT CAUSE The documentation example in `docs/extend/plugins_volume.md` references the deprecated ScatterHQ/Flocker project, which is no longer maintained. This creates confusion for users as Flocker is not actively developed and may not work with current Docker versions. The fix involves updating the example to use a more appropriate volume plugin example, such as the built-in `local` driver or suggesting a modern alternative like `local-persist`. ### CODE FIX ```markdown ### Example: Using the Built-in Local Volume Plugin To create and use a volume with the built-in local driver: ```bash docker volume create my_volume docker run -it --rm -v my_volume:/data ubuntu /bin/bash ``` ### Alternative Example: Using `local-persist` Plugin For persistent local volumes (if needed), install the `local-persist` plugin: ```bash docker plugin install --disable=docker.io local-persist:latest docker volume create --driver local-persist my_data_volume docker run -it --rm --volume-driver local-persist -v my_data_volume:/data ubuntu /bin/bash ``` ### Deprecated Note The Flocker example in the documentation is removed as it is deprecated. Users should use the built-in `local` driver or modern third-party plugins instead. ```